Dobby machines



Aug. 5, 1969 M. FAVRE 3,459,236

DOBBY MACHINES Filed Jan. 29, 1958 Fla.

United States Patent 3,459,236 DOBBY MACHINES Marcel Favre, Faverges, France, assignor to Gebr. Staubllc & Co., Horgen, Switzerland Filed Jan. 29, 1968, Ser. No. 701,198 Claims priority, application Switzerland, Jan. 30, 1967,

1,319/ 67 Int. Cl. D03c 1/06 U.S. Cl. 139--71 7 Claims ABSTRACT OF THE DISCLOSURE In order to avoid undesired disengagement of the attachment hooks on the baulk of a dobby machine from the arrester hooks or other pull members upon sudden stoppage of the machine, for example upon yarn breakage, each of the arrester hooks is spring biased toward the respective attachment hook or pull member and stops are provided on the baulk to limit pivotal movement of the attachment hooks by the springs.

This invention relates to dobby machines having means for controlling and operating the heald shafts.

Yarn breakages and other irregularities in the operation of a loom result in sudden stoppages of all movements. A sudden stoppage of the up and down movements of the heald shafts causes a reaction on the heald shaft control means, which is particularly important in the case of yarn breakage because it occurs at the moment of greatest acceleration of the heald shafts.

It is found that the attachment hooks of the baulks and levers, or the attachment hooks and arrester hooks, can become disengaged because the sudden arresting of the heald shafts reacts through the reciprocating members, jack levers and baulks on the attachment hooks to disengage them from the arrester hooks. This results in further yarn breakages and damage to the heald shaft operating members and to cast iron parts, e.g. jack-levers, which maybe broken.

The arrangement according to the invention comprises a baulk with attachment hooks at its ends, which cooperate with arrester hooks or pull members and with bars pushing the baulk ends or attachment hooks, each attachment hook having attached to it one end of a spring, the other end of which is attached to the baulk or to another hook of the same baulk, so that when the connection of the hooks is released, the tip of the attachment hook follows the tip of the arrester hook or pull member thus rendering impossible an undesired disconnection.

The springs may be tension or compression springs or also spiral springs.

A constructional example of an arrangement according to the invention is illustrated by Way of example in the accompanying drawings in which:

FIG. 1 shows diagrammatically in side elevation the arrangement of the mechanism for control and movement of a shaft, and

FIGS. 2 and 3 are similar partial views showing modifications.

The control is effected by means of a punched sheet or card 1 which is driven by the card cylinder 2 and cooperates with reading needles 16. According to the position of pulling needles 3 carried by the reading needles 16, the pulling needles 3 are actuated by reciprocating bars 4, whereby the positions of actuating members shown as arrester hooks 5 are controlled. The hooks 5 are loosely mounted on stationary rods 6 and are acted upon by tension springs 7.

The heald shaft, which is not shown in the drawings, is moved by a jack-lever 8 which is rockably mounted on a stationary shaft 9 and to which the pull-member A to the heald shaft is attached. The jack-lever 8 is pivotally connected at 20 to the center of a baulk 10 which has at each end an attachment hook 11. Two bars 12 carry out toand-fro swinging movements and push the attachment hooks 11 alternately into an engagement position relative to the arrester hooks 5. In the position illustrated, both arrester hooks are in the engagement position, and the attachment hooks 11 are held in the engaged position. The upper hook 5 has dropped into the attachment hook 11 which has been pushed by the upper bar 12, while the lower arrester hook 5 was already engaged during the previous pick of the loom.

If the loom is suddenly stopped in an intermediate position of the bars 12, a pressure might be exerted by the jack-lever 8 on the baulk 10 which would result in loosening the grip of the hooks 5 0n the hooks 11, thus enabling a disengagement of the hook 5 from the hook 11 and a jump-back of the baulk onto the bar 12. This would result in a simultaneous dropping of the corresponding heald shaft. According to the invention, however, a spring 13 is arranged between each attachment hook 11 and the baulk 10, tending to keep the tip 14 of the hook 11 in contact with the arrester hook 5 and to prevent disengagement. In order to limit the rocking movement of the hooks 5 and 11, stops 17 and 18 may be provided on the machine frame and the ends of the baulk, respectively.

As illustrated in FIG. 2, the two tension springs 13 can be replaced by a single spring 13', with one end attached to each attachment hook 11, so as to cause the tips 14 of the attachment hooks to follow the arrester hooks 5. Instead of the tension springs, compression springs, or spiral springs 13" wound around the pivots 15 of the attachment hooks as illustrated in FIG. 3 can be used.

The provision of a spring 13 in conjunction with the attachment hook 11 has the result that the attachment hook follows a premature movement of the arrester hook 5 and so maintains contact and prevents the heald shaft from jumping back. Thus, when the bar 12 does not exert pressure on the bearing surface of the attachment hook, this hook will, under the influence of its spring, follow the arrester hook when it tends to become released.

While a preferred embodiment of the invention has been shown by way of example in the drawing, it will be understood that the invention is in no way limited to this embodiment.

What I claim is:

1. In a dobby machine having a frame and heald shaft, controlling and operating means comprising a jack-lever connected to said heald shaft, a baulk pivotally connected to said jack-lever, an attachment hook pivotally mounted on each end of said baulk, arresting members selectively engageable with said attachment hooks, said jack-lever being biased to pull said attachment hooks away from said arresting members, spring means biasing said attachment hooks to swing about their pivot relative to said baulk in a direction toward said arresting members, means for limiting movement of said attachment hooks relative to said baulk by said spring means, actuating members periodically and alternately engageable with said attachment hooks to position said hooks and said baulk, pattern controlled means for moving said arresting members selectively into and out of position to engage said attachment hooks when engaged by said actuating members, said spring means yieldably holding said attachment hooks in engagement with said arresting members When said arresting members are in hook-engaging position and said attachment hooks are not engaged by said actuating means so that, in the event the pull on said attachment hooks by said baulk is released, said hooks follow the arresting members to avoid an undesired disconnection of said attachment hooks from said arresting members.

2. A machine according to claim 1, in which said spring means comprises tension springs each having one end attached to the baulk and the other end attached to the respective attachment hook.

3. A machine according to claim 1, in which said spring means comprises a single tension spring having its ends attached respectively to said attachment hooks.

4. A machine according to claim 1, in which said spring means comprises a spiral spring arranged around the pivot of each of said attachment hooks respectively.

5. A machine according to claim 1, in which said limiting means comprises stops provided on the baulk for limiting pivotal movement of said hooks by said spring means.

6. A machine according to claim 1, in which said arresting members comprise arrester hooks rockable about stationary supports.

7. A machine according to claim 6, further comprising spring means biasing said arrester hooks for rocking movement about said supports, and stops on the machine frame for limiting the rocking movement of said arrester hooks by said spring means.

References Cited UNITED STATES PATENTS 2,705,506 4/1955 Staubli 139-71 2,751,938 6/1956 Staubli et al 139-74 X 3,225,792 12/1965 Piazzolla et al. l3971 3,285,291 11/1966 Favre 139-74 X 3,378,038 4/1968 Hadinec l3966 v FOREIGN PATENTS 219,515 2/ 1962 Austria.

JAMES KEE CHI, Primary Examiner 

